As someone who has just re-read this manga, I can firmly say for those who have not read this yet, to view the relationship between mc and roxanne as a realistic slave master relationship, no romance shit where mc saves her or gives her the option of being free. The best comparison i can make of their relationship is that of a realistic dog and its master. If you re-read this and view it as a dog and master relationship, then everything makes sense. Like why would you want to let your dog go free?